From the synthesis of past research literatures both in Thailand and other countries, it was found that lifelong learning was emphasized, but there was no study determining environmental education indicators for lifelong learning. The researchers, therefore, tried to study the environmental education factors and indicators for lifelong learning, based on a systematic analysis in order to fulfill the principles of environmental education in the Belgrade Charter and the environmental guideline for sustainable development. Consequently, the research operation consisted of two phases, the first and the second phases. The first phase was factors and indicators identification, survey, and evaluation, have been done using in-dept interview and Delphi techniques. The samples, were purposively selected, consisted of 9 administrators and teachers, 35 students from three Royal Honored Environmental Creative Award-winner schools, and 19 experts. In the second phase, that was 20 experts opinions were evaluated in terms of validity, utility, understandable, appropriateness and feasibility of indicators.
The result of both two phases indicated the environmental education factors and lifelong learning indicators comprised of two dimensions, including internal and external dimensions of the schools. The internal dimension comprised of 188 indicators and 12 factors, divided into three components; input, process and output, in accordance with Johnstone (1981). The external dimension comprised of 35 indicators and two factors with 18 learner family background indicators and 17 learner-community environment indicators.
The research resulted could be applicable for planning and management of environmental education in promoting lifelong learning at general education level of Thailand schooling systems.